Electric switch



A. A. JOHNSON May 7, 1935.

ELECTRIC SWITCH Filed Dec. 19, 1929 MJL@ Patented May 7, 1935 f-UfNlTsD As'rlvrlazs ELECTRIC SWITCH Arthur A. Johnson, New Bedford, Mass., assignor to John I. Paulding, Inc., New Bedford, Mass., Y a corporationof Massachusetts Application December 19, 1929, Serial lNo. 415,342

2 Claims. (Cl. 173-346) Y t t l the usual bushing lzlfor attachment tothe nipple- My invention relates to electric switches and is exemplified in a switchfor electric lamps of the key type. y t

The main object of the invention is the pro- 5 vision of a switch of simple and eicient construction which may be assembled' rapidly andat a low cost.

Other objects of the invention will'be more specifically pointed out and described herein-v after. I

My'` invention contemplates a switch structure comprisinga cam member having an inclined cam portion of such form that when the'cam memberV is rotated the inclination of said cam portion is reversed whereby a rocker member is operated tol close or break a circuit'by engagement with or separation from suitable contacts. In the preferred form of the invention, the cammember is made in the form of 'a spindle having a cam portioninclined to its longitudinal axis so that when-the spindle is rotated on said axis through-an arc of one hundred and eighty degrees, said cam portion is reversed in inclination.v

' In the drawing illustrating one form of the invention, Figure 1 is a vertical central sectional view ofk an electric lamp socket adapted to be operated in accordance with my invention showingthe rotary cam member inelevation; Fig. 2 is a central sectional view on line 2--2 in Fig.V 1 looking from right to left; Fig. 3 -is across-sectional view on line 3 3 in Fig. 1 looking upwardly and showing the switch mechanism in elevation; Fig. 4 is a bottom end View of the xture; Fig. 5 isa top plan view of Vthe insulatingbody, one of 35v the xed contacts being'omitted to show the form of recess therefor; Fig. 6 is a sectional viewlon line 6-6 in Fig. 5 showing the means for fastening the screw shell tothe insulating bodyjFig. '7 is a detail sectional view on line 'l-'l in Fig. 5; Fig.'8 is a detail sectional view on line 8--8 in Fig. 3; Fig.v9 is a plan view of the insulating disk for closing the chamber in the insulating body' looking downwardly in Fig. 1; and Fig. 10 is a side elevation of" the actuating spring.

In the drawing, the switch of my invention is shown as applied to an electric lamp socketrbut- 555 May 25,1926, comprises'a cap portion 'l0 having f an electric fixture and a shell portion I4 providedwith a 4key slot i6. vWithin the cap and shell'is mounted respectivelyV insulating linings Il and I8. An insulating body 20- carries the switch mechanism and has attached thereto a screw shell 22 for receiving thev threaded-portion of an electric lamp, these parts being mountedA within the shell of the socket.'l

The insulating body 20 is provided in its lower face'with an'open rectangular recess or chamber 24 having a central sub-recess 26 within whichl recesses `is mounted the switch mechanism. 'In- V terposed between the screw shell and lower face 0f the insulating body and `covering the recess oi" chamber 24, is a disk 2l of libre or other insulatingV material carrying a contact member 28', one end of which is turned over on the lower side of the disk as a free end to serve as a lamp contact 30 and the other end of whichV is turned through a slot 3l ink the disk and provided on one side with an uputrnedl contact member 32 which projectsinto the recess 24. The body portionofthe con` tact member is secured to the disk by a lug 34 on each side thereof which' is turned through a suitablehole 35 in the disk 4and clamped on the upper side thereby for holding the contact memberv fixed firmly to the disk. The latter andthe screw shell are secured to the insulating body by two screws 36 and 3l vmounted in suitable bores in the insulating bodyk and holes 38 in the disk, the rst having its upper end threaded through a square nut 39 set in a square recess 40in the upper face of the insulating body and the second threaded into a right-angled terminal member 4| carrying a binding screw 42 to which may be connected one of the wires or conductors 43 (Fig. 6)`. Suitable Washers 44 may be interposed between the heads of the screws and the inturned earsf45 of the base of the lscrew shell. The terminal 4| is fastened in position on a shelf in an outer recess 41 formed in the insulating body and is connected to the screw shell. Set ina similarouter recess on the other side of the insulating body is a right-angled terminal plate 5I carrying a binding screw 53 for the connection of the other wire 54 of the circuit thereto; said terminal plate being connected by a screw 56 to the'square butt 51 of a xed contact 58 extending into the chamber 24.'

Mounted within the recess 24 and the recess l26 is a switch mechanism constructed in accordance with my invention and comprising a rotary cam member 60 a rockermember 62 and an actuating spring64 (Figs. 1 and 2). 'The rotary cam member is in the form of a spindle designatedas having approximately midway its length a cam portion 66 which is inclined to the longitudinal axis of the spindle and which is formed by bending that portion of the spindle laterally, the cam portion being connected at its two ends to the spindle by oppositelyinclined portions 61 and 68 respectively. The cam portion is preferably so formed that its longitudinal axis and the longitudinal axes ofthe portions 61 and 68 lie in a plane which passes through the longitudinal axis of the main portions of the spindle. The upper and lower surfaces of the cam portion as shown in Fig. 1 may be flattened to form cam surfaces to be engaged by the rocker member. The latter member is preferably stamped out of sheet material and is flat and U-shaped in plan having its4 two ends 'l0 extended outwardly in a lateral direction in order to engage the fixed contacts SZfand 58. The outer edge of the head of the rocker member is provided with two recesses Vthereby forming a central projecting lug 'I2y around which isreceived one endv of the actuating spring 64 ofl helical form having its other end abutting the bottom of the sub-recess, the sub-recess being formed: to hold that end of the spring against lateral movement while permitting a slight pivotal movement of the spring in the operation of the rocker member (Figs. l and 2). The free end of the spindle is mounted in a hole'M formed in the insulating bodyl and its other end is held in position at the bottom of agroove 15. by a small piece l5 tting in suitable grooves 'il which isrheld in place by thedisk 21. Upon the outer end ofthe cam member is mounted a key 18 for turning it to open and close the switch. y

In orderto insure a rapid and instantaneous break between the fixed contacts and the rocker member when the latter is operated to break the circuit, the two ends 3G and 8| of the actuating spring 64 are closed, sothatthe planes of said ends are approximately perpendicular to the central axis of the spring, and the floor of the sub-l recess 26v is oblique, being slanted toward the fixedr contacts as shown in Fig. 1. As a result of thisL construction, when the actuating spring is compressed by the initial turning of the cam member and before thelatter has been turned; into apposition permitting the rocker member to be rocked away from the contacts, the entire force of the spring acts in a direction to hold the rocker member in tight engagement with the fixed contacts. When the cam member has been rotated` to a point which permits the rocker member to move, it is then snapped away from the fixed contacts. instantaneously thereby preventing arcing. The elimination of arcing is important because it prevents burning or fusing of the contacts andenables the switch to carry a greater load.

The operation of the switch'is easily understood. In Figs.l 1 andk 2 the switch is shown in closed position with the two ends 'lllv of the rocker member 62 in engagement with the fixed contacts 32 and 58 thereby bridging the space` between said tWo contacts and closing the 4circuit for lighting a lamp mounted in the screw shell. In this position, the actuating spring 64 being under compression forces the rocker member down into the valley formed by the junction of the top cam surface of the cam portion 66 with the oppositely inclined portion 61 and holds it there. To open Vthe circuit, the spindle 6U is turned through an arc of one hundred and eighty degreesv by the manipulation of the key 18. In this operation the rocker member is raised, thereby compressing the actuating spring and requires the exertion of a slight force to raise `the rocker member against the compression of the spring and when the spindle has been partially turned, the pressure of the spring will cause the rocker member to be rocked and the remaining movement of the spindle through its areV of vone. hundred and eighty. degrees to be completed automatically. Although the rocker memberis loosely mounted on the cam member, any lateral movement thereof `is prevented by engagement between the sides of the rocker member .and the side walls of the recesses in the insulating body (Fig. 2).

The assembling of the parts' is simple and canV be accomplished expeditiously since the switch parts do not require to be fastened withinV theA insulating'body but may be placed inthe recesses in their normal relation, the end of the cam member being inserted in the hole in the insulating body and its-'main portion being forced down into 'the groove after which the small piece 1.6 isinserted in the groove 1.1, the disk 21 placed in position with the screw shell and secured to the insulating body by, the two screws 36 and. 311, the terminal plate 5|V and contact member 58 having previously been fastened to the insulating body by the screw 56. The assembling of the entire structure requires, therefore, the manipulation of only three screws and therefore can be accomplished in` a most expeditiousmanner.

, It will be observed that my switch is extremely simple in construction comprising but three main elements which are loosely mounted in. the insulating body and held in normal operative position at all times-by their relations to each other and by the form of the recesses and the attachment tothe insulating body of the disk andscrew shell. Because of this simple construction, the switch mechanism is positive in operation, durable and willr last throughout the life ofthe actuating. spring.

It is to. be understood that the form` of thel invention shown and described herein is merely illustrative of the invention and that it is not to be limited to the particular form shown since it` may be embodied in other forms within, the scope of the following claims.

- What I claim isz- 1. An electric switch comprising a recessed insulating body, a' pair of xed contacts mountedv in separated relation in vsaid recess, a rotary spindle. having an inclined cam portion adapted to be reversed in inclination by the rotation of said spindle, a- U-shaped rocker member loosely mounted on and straddling the cam portion of said rotary spindle, an actuating spring for holding said rocker member in engagement with said rotary spindle, said spring having closed ends, one abuttingsaid rocker member and the other the bottom of said recess and said bottom being in a plane perpendicular to the plane of the contacting surfaces of said fixed, contacts to prevent arcing vwhen the engagement between the rocker Arocker member to hold it in constant engagementv with said cam portion and to move yit thereon from one valley to the other whenever said spindle isrotated in order to rock the free ends of said rocker member into and out of bridging engagement with said fixed contacts, the floor of said recess being oblique to the transverse axis of said insulating body and perpendicular to thev plane of the contacting surfaces of said fixed contacts to preventarcing when the engagement between the rocker member and said contacts is 10 broken by the operation of said rotatable spindle.

ARTHUR A. JOHNSON. 

